Antifreeze noncorrosive solution



Patented Apr. 24, 1934 UNITED STATES PATENT OFFICE ANTIFREEZE NONCORROSIVE SOLUTION No Drawing.

11 Claims.

This invention relates to a new composition of matter having both non-corrosive and anti-freezing properties and which is particularly adapted for' use in the cooling systems of water-cooled internal combustion engines.

It is well known that in the operation of automotive vehicles, particularly in the winter months, it is necessary, when using those employing water-cooling systems, to use as a cooling me,-

dium a liquid which will not freeze under the conditions of operation. Various so-called antifreezing liquids have been proposed for this purpose, such, for example, as ethyl alcohol, glycerol, ethylene glycol, and aqueous solutions of inorganic salts. Thepolyhydroxy alcohols which are used to some extent have proven rather expensive when leaks occur in the cooling systems; the employment of inorganic salts in the radiator solutions are prone to effect undue corrosion of the various parts thereof, and while ethyl alcohol has proven to be inexpensive, nevertheless when used alone, it efiects considerable corrosion of the metal parts of the radiators in contact with it.

An object of the present invention is to provide a composition of matter which not only has a low freezing point but likewise inhibits corrosion. A further object of this invention is to provide such a composition of matter, particularly for use in internal combustion engines, and in 39 which the corrosive action of the anti-freeze liquid and the water is inhibited. Other objects will hereinafter appear.

I have found that a solution containing the water soluble lower aliphatic alcohols and principally ethanol, methonal, and propanol, in which there has been dissolved an alkyl or aryl antimonyl tartrate of anamino derivative thereof, for example the methyl, ethyl, propyl, butyl, etc. antimonyl tartrates;- the benzyl, tollyl, phenyl, etc. antimonyl tartrates; methyl amine, ethyl amine, propyl amine, butyl amine, benzyl amine, ethylene diamine, urea, naphthyl amine, aniline antimony tartrate, and equivalent antimonyl tartrates. In' suitable proportions these inhibitors may be used in the cooling systems of internal combustion engines without fear of the corrosion of the oxidizable metals, such as brass,'alum.inum, steel, or other metals found in such apparatus by the water or acidic impurities present and with the assurance that, even tho the temperature of the solution becomes excessive, there will-result substantially no corrosion ofthe metal surfaces. As the above organic antimonyl tartrates are usually very soluble in the alcohols and especially methanol they can be readily incorporated there- Application December 23, 1932, Serial No. 648,591

in by simple solution in the alcohol prior to its introduction into the cooling system of the automobile. The addition of such an alcohol salt solution to the automobile radiator will protect the metallic parts thereof from corrosion as well as imparting thereto the freezing point lowering of the radiator solution in proportion to the amount of the alcohol used.

The corrosion in the radiators of automotive vehicles or stationary internal combustion engines will, of course, be governed by many factors, such, for instance, as the impurities in the water present, the' purity of the alcohols, etc. Generally speaking, however, a concentration within the radiator of from 0.1% to 0.5% of the tartrate will give a solution having substantially no corrosive action on the oxidizable metals with which said solution may contact.

While various aliphatic alcohols may be used in conjunction with the tartrate, I prefer methanol, as it has several advantages over-the other lower aliphatic alcohols. A smaller amount of methanol is required to eflect the same freezing point lowering of a solution than is required to effect the same freezing point lowering by the addition of the higher molecular weight alcohols and consequently it is less expensive to use even when their cost per gallon is the same. Furthermore, an aqueous solution protected against freezing to 20 F. will have a boiling point of 199 F. if methanol is used and 194 F. if ethanol,-at 10 F. the relative boiling points are 193 F. for the methanol protected solution and 187 F. for the ethanol protected solution. Obviously a smaller amount of methanol will be lost by evaporation under similar operating conditions. I

An anti-freezing, non-corrosive composition for addition to the water-cooling system of internal combustion engines, in accord with my invention, should contain suificient amount of the tartrate to give adequate protection from corrosion. This should be true even tho the freezing point of the radiator solution is lowered only to a temperature of, say, 15 F. This result, is realized when the methanol solution contains in the neighborhood of, say, 1 to 3% of the organic antimonyl tartrate, and further a concentration even as low as 0.1% of these tartrates or the organic antimonyl tartrates alone or mixed with other corrosion inhibitors is sufiicient to give worthwhile corrosion inhibiting effect both in the radiator when diluted with waterand in the container prior to dilution. The amount of methanal or other aliphatic alcohol required to give the desired lowering of the freezing point will be determined, of course, by the amount thereof added to the aqueous solution. The amount of methoxidizable metals with which the anti-freeze radiator composition of automobiles is in contact, which comprises contacting the anti-freeze omposition containing a water soluble aliphatic alcohol with the oxidizable metals in the presence of a relatively small amount of a compound selected from the group consisting of alkyl and of aryl antimonyl tartrates.

2. A process for inhibiting the corrosion of the oxidizable metals with which the anti-freeze radiator composition of automobiles is in contact, which comprises contacting the anti-freeze composition containing a water soluble aliphatic alcohol with the oxidizable metals in the presence of a compound selected from the group consisting of an amino derivative of an alkyl and an aryl antimonyl tartrate.

3. A process for inhibiting the corrosion of the I oxidizable metals with which the anti-freeze radiator composition of automobiles is incontact, which comprises contacting the anti-freeze composition containing a water soluble aliphatic a1- cohol with the oxidizable metals in the presence of .1 to 5% of a compound selected from the group consisting of alkyl and of aryl antimonyl tartrates. I

4. Aprocess for inhibiting the corrosion of the oxidizable metals with which the anti-freeze radiator composition of automobiles is in contact,

which comprises contacting the anti-freeze composition containing a water soluble aliphatic alcohol with the oxidizable metals in the presence of .1 to .5% of a compound selected from the group consisting of an amino derivative of an alkyl and of an aryl antimonyl tartrate.

composition containing an aqueous methanol 0 solution and from 0.1 to 0.5% of aniline antimony tartrate.

6. A process for inhibiting the corrosion of oxidizable metals with "which theflliquid'antifreeze radiator compositions of automobiles is in contact, which comprises contacting the antifreeze composition containing an aqueous methanol solution and from 0.1 to 0.5% of butyl amine antimony tartrate.

'7. A process for inhibiting the corrosion o oxidizable metals with which the liquid antifreeze radiator compositions of automobiles is in contact, which comprises contacting the antifreezecomposition' containing an aqueous methanol solution and from 0.1 to 0.5% of ethyl antimony tartrate.

8. An automobile anti-freeze which is substantially non-corrosive towards the oxidizable metals of the automobile with which it contacts, which comprises a water soluble alcohol and a compound selected from the group consisting of alkyl and of aryl antimonyl tartrates.

9. An automobile anti-freeze which is sub-'- stantially non-corrosive towards the oxidizable metals of the automobile with which it contacts, which comprises a water soluble alcohol and a compound selected from the group consisting of an amino derivative of an alkyl and of an aryl antimonyl tartrate.

10. An automobile anti-freeze which is sub--11).

tartrate.

' JULIUS F. T. BERLINEB. 

